MESSAGE BOARDS
If you make your email public on message boards, there are people whose only purpose for accessing boards and profiles is to get emails that they can spam.
There are two ways to avoid getting spam to your email accounts:
1) You can create a special email account with one of the many free providers, and use it solely for the purpose of joining message boards.
2) Wherever you go, make sure that you hide your email account from the public view.
EMAIL FORWARDING
Have you ever received an email forward from someone? Have you ever checked out all the email addresses of other people, some of whom you have no idea who they are?
Well, the truth is, some of these emails can actually fall in the hands of spammers, and, guess what? If your email address is listed in one of the forwarded messages, you are now a new target of spamming. Just remember, that some people don't even know eachother, so you can't possibly know who is seeing your email address.
UNSUBSCRIBE LINKS
If you know that you have not subscribed to a specific newsletter, and the name sounds phony, you need to be careful when clicking on links that are supposed to unsubscribe you from the mailing list. These might just be links that will verify that your email account is open for spamming -- triggering yet more spam! Now, if email from this same source perists, then it would probably be best if you go ahead and click on that unsubscribe link -- that would be your last solution.
So, all I am saying here is that you need to be careful where you post your email, who you forward and from whom you receive forwarded messages, and you need to be careful about what links you click on.
Just my advise...